The present invention relates to folding bed frame structures and more particularly to folding bed frames of the type specially adapted for opening and folding articulation from and into the enclosure of a sofa frame or the like.
Convertible sofa beds having widely varying folding bed frame structures are in common use. Characteristically, the folding bed frames of such sofa beds are provided with a plurality of bed sections pivotally connected in end-to-end relation and operatively associated with a linkage arrangement for mounting within the rectangular enclosure of a sofa bed frame defined by its side frame members, which normally comprise the sofa arm rests, its sofa back and a front rail, to be articulable between a folded or retracted condition stored within the sofa frame enclosure and a horizontally extended condition disposed and extending outwardly from the enclosure over and beyond the front rail of the sofa frame.
Substantial activity has heretofore been devoted to the improvement of folding bed frame structures of this type, a significant amount of which activity has been directed toward the common objective of providing a simple linkage arrangement which is compactly foldable and which requires a minimal amount of space for articulating the bed sections into and out of the enclosure of the sofa frame. The linkage arrangements of many of the relatively early folding bed frame designs provided a support and actuating linkage designed for affixation interiorly to a sofa frame which linkage operatively connected with both the head support section of the bed frame structure arranged to be disposed most rearwardly, i.e., toward the sofa back in the extended condition of the frame, and the intermediate bed section pivotably connected to the head section, the intermediate section normally being the main supporting section of the extended bed. To avoid engagement with the seat back portion of the sofa frame in the folding and unfolding operation of the bed frame, some such folding bed frame structures were arranged to fold and be stored within the sofa frame below and forwardly of the seat back thereof, an example of such structures being disclosed in W. C. Rogers, Jr., U.S. Pat. No. 3,247,526. This manner of storage arrangement often resulted in the non-use of a significant amount of the available storage space within the sofa frame rearwardly below the seat back, as can be seen in the latter cited patent. Moreover, while being generally operable for folding and unfolding the bed sections of the bed frame, the support and actuating linkages of such bed frame structures generally occupied a greater than desirable storage area within the sofa frame in the folded condition and required a greater than desirable area of movement in unfolding to the extended position.
In attempting to better use the available storage space within the sofa frame, other folding bed frame structures were arranged such that a part of the linkage arrangement and/or the head support section would be disposed rearwardly in an upstanding disposition in the folded condition thereby to take advantage of the available storage space within the hollow seat back of the sofa frame. Such structures necessarily presented problems in designing the linkage arrangement to articulate the portions of the structure thus stored around the lower forward portion of the seat back in folding and unfolding operation. Characteristically, the satisfaction of this necessity resulted in the provision of a support and actuating linkage of significantly increased complication which required a greater amount of storage and operational space, the sofas which incorporated such bed frame structures accordingly normally being constructed with disproportionately deep seat backs. Examples of this type of folding bed structure are disclosed in Woller U.S. Pat. No. 2,352,989, Rogers U.S. Pat. Nos. 3,165,757 and 3,298,041, Rea U.S. Pat. No. 3,258,786, and Pokorny U.S. Pat. Nos. 3,178,731 and 3,321,777. As will be appreciated, such bed frame structures thus generally defeated the purpose for which they were designed.
One alternate linkage arrangement which has had significant attention provides a support and actuating linkage which operatively directly connects only to the main intermediate bed section and utilizes an associated actuating linkage arrangement to control the folding and unfolding movement of the head support section, thereby freeing the head section of complicated associated support linkage so that it may be folded uprightly within a relatively narrow hollow seat back. Examples of such bed frame structures are disclosed in Rogers U.S. Pat. No. 3,284,811, Pokorny U.S. Pat. No. 3,416,168, and Mikos U.S. Pat. No. 3,516,096. While such bed frame structures essentially represent the present state of the art, certain problems still accompany their use. Initially, since the head support section folds within the seat back which normally will be narrow for aesthetic furniture design purposes, there exists the requirement of a support and actuating linkage arrangement which will articulate the head section around the seat back. Generally, the linkage arrangement will provide for an initial lowering of the rearward portion of the folded structure in moving from the folded to extended condition and accordingly requires a greater than desirable area beneath the folded structure to accomodate such movement. Additionally, the head section of bed frame structures of this type are sometimes inadequately supported in the extended condition producing a tendency for downward pivoting of the head section about its pivotal connection with the intermediate section to which it is connected beyond a horizontal disposition under loads.
An associated problem with these and all other folding bed frame structures which are designed to fold in a manner whereby a portion thereof assumes an upstanding disposition for storage within the seat back of a sofa frame is that structures of this type generally are not susceptible of compact stacking for shipping and storage thereof. Substantially none of the furniture manufacturers which produce sofa beds manufacture the bed frame structures incorporated therein. Such structures are instead purchased from other manufacturers specializing in their production and, accordingly, must be shipped from the manufacturer thereof to the furniture manufacturer. The compact folding of the structures to a stackable disposition for storage or shipment is therefore, a concern equally important to those discussed above. Preferably, the structures should be foldable to a compact, generally rectangular prismatic shape. Metayer U.S. Pat. No. 3,903,553 discloses a bed frame structure wherein the linkage arrangement provides for the automatic operative folding of the head support section between the forwardmost bed section, i.e., the foot support section, and the main intermediate section thereof. While this bed frame structure therefore better facilitates shipping of the frame than do other bed frames, it is precluded from utilizing the advantage of folding the head section within the seat back in the finished sofa bed. To this end, Wong U.S. Pat. No. 3,984,883, discloses the provision of a disconnectable actuating link in the head section actuating linkage whereby such linkage can be disconnected so that the head section may be pivoted forwardly between the foot support section and the intermediate section in the folded condition to provide a compact folding of the structure which will facilitate shipping and storage thereof. Reconnection of the linkage is performed by the furniture manufacturer for ordinary operative folding and unfolding of the bed frame structure.
In contrast to the above, the present invention provides a folding bed frame structure of the type having a head section free and unsupported directly by the support linkage of the structure and adapted to move between the folded and extended positions of the structure so as to permit disposition in its folded condition within the seat back of a sofa frame, wherein a unique bracing arrangement is provided to rigidly maintain the head section horizontally in the extended condition, a stop arrangement is provided to cause the head section to move in a tighter, more compact arcuate path during its initial and final portions of movement, respectively, from the folded to the extended position and from the extended to the folded position, and a combined arrangement of a partially independently foldable head section with a lost motion arrangement in the head section actuating linkage is provided for selective folding of the head section between the foot and main intermediate bed sections during folding of the bed frame from its extended in its folded disposition.